I have quite complex migration for some legacy non drupal site to migrate it into D7. The whole migration works fine but it turned out that source user passwords are salted and hashed with MD5. Because they are salted I can't do this in my migration class:
$this->destination = new MigrateDestinationUser(array('md5_passwords' => TRUE));
I've found this solution which boils down to reimplementation of original hashing algorithm in new drupal site. I don't like this solution because it decreases security of the site and throws away whole D7 password hashing code.
Something tells me that the only way to migrate those old passwords and keep the drupal hashing algorithm is to copy-paste whole
includes/password.inc and add "temporary" hashing algorithm from the old non-drupal site in similar way drupal core handles old MD5 passwords without salt.
Or maybe there is a better way to migrate those old passwords?